Such a method is disclosed in published German patent application DE-OS 37 33 992. In this publication, a method for controlling the metering of fuel for a multi-cylinder engine is described. A fuel pump driven by the engine has several outlets for connecting to corresponding injection nozzles of the engine. Electro-magnetically actuable valves control the quantity of the fuel to be pumped through each outlet. The valves are controlled by a power module in dependence upon a fuel-quantity signal. A comparison circuit compares the engine speed over a working stroke of the engine with the engine speed over the previous working stroke. A distributor device supplies drive signals specific to particular cylinders to the power module in dependence upon this comparison. This method has the disadvantage that the compensating operations are carried out for each combustion cycle and this is associated with a considerable use of computing time.
A method for influencing control variables of an engine is known from U.S. Pat. No. 4,688,535. Vibrating and shaking at idle are based on different fuel quantities which are supplied to the individual cylinders. To prevent the vibrating and shaking, a separate control is provided for each cylinder which determines the quantity of fuel to be injected in dependence upon a desired value and an actual value. Accordingly, a controller is required for each cylinder and this makes it necessary to provide a large number of components. In this method, the corrections must be newly computed for each metering.
Furthermore, an arrangement for drift compensation of fuel-metering systems is known from U.S. Pat. No. 4,426,980. In this arrangement, it is not the metered quantity which is controlled but only the position of an actuator determining quantity. It is an object of this arrangement to maintain the association which initially applied between the total injected fuel quantity and the position signal of the quantity-determining member. Variations in the fuel metered to the individual cylinders are not compensated.